Both species are serious invaders in climatically suitable countries across the world, including Australia where C. grandiflora is listed as a Weed of National Significance.

In South Africa both Cryptostegia species are proposed for listing under NEMBA as category 1b species.Some occurrence records exit for these species in urban and natural areas in Southern Africa and one of this species is (C grandiflora) is well established and invasive along the Mogalakwena River in Limpopo Province.

As a result, there is concern that C. grandiflora and C. madagascarensis could potentially pose a risk to sensitive unique riparian areas in South Africa.

Few occurrence data exist for these species in Southern Africa making it difficult to determine the species’ current distributions.

Pilot surveys conducted along the Mogalakwena River in the Limpopo province have shown that some areas have densities as high as 2000 plants, although these infestations occur no further than 40m away from the Mogalakwena River.